Deborah Hersman, president and chief executive officer of the National Safety Council, at a National Highway Transportation Safety Administration conference in Arlington, Virginia, Oct. 5, 2016.

Waymo, the Alphabet subsidiary on the cusp of launching the first autonomous rideshare service in the U.S., has hired a former top safety regulator to ensure the company’s fleet of robotaxis operate safely.

Deborah Hersman, who was chairwoman of the National Transportation Safety Board in the Obama administration, will become chief safety officer for Waymo starting in January. She will focus on ensuring the safe operation of hundreds of driverless vehicles that are expected to shuttle passengers.

“I’ve dedicated my career to promoting safety in our communities, and I’m joining Waymo because of the potential to make an even greater impact on reducing road injuries and fatalities,” Hersman said in a statement released by Waymo. Hersman has been CEO of the National Safety Council for the last four years.

Waymo CEO John Krafcik praised Hersman’s career of focusing on safe transportation. “As we begin to make our self-driving cars available to the public, safety will continue to be front-and-center of everything we do,” he said in statement.

The move comes just weeks before Waymo launches the country’s first autonomous ride-share service in metropolitan Phoenix. The company has been testing the service for months with a limited number of passengers riding in Waymo autonomous minivans to make short trips in the Phoenix area.

Ever since Waymo, formerly known as the Google Self-Driving Car Project, start testing autonomous vehicles in 2010, critics have questioned the safety of driverless vehicles. Those questions became more pronounced as a growing number of automakers, tech firms and ride-hailing companies have joined the race to develop driverless cars. Earlier this year, an Uber test vehicle in autonomous-mode hit and killed a pedestrian just outside Phoenix. The deadly accident and video showing the Uber test vehicle failing to identify the pedestrian as she crossed the street at night sparked a national debate as to whether robotaxis are ready for public use.

Waymo is well aware of those concerns and has been emphasizing its push to ensure its vehicles are safe.

In addition to signing Hersman, Waymo has also hired its first chief commercial officer, Amee Chande, who will oversee business strategy, operations, and strategic partnerships as the company starts to monetize its work with driverless vehicles. Chande joins Waymo after serving as managing director of global strategy and operations for Alibaba Group.